Microspectrofluorometry in biogenic amine research

Fluorescence histochemical techniques for catecholamines as tools in neurobiology

Formaldehyde-induced and glyoxylic-acid-induced fluorescence histochemistry permits the tissue localization of catecholamines in the central nervous system (CNS) and peripheral nervous system (PNS), and in culture. Counterstains such as ethidium bromide provide excellent background identification of specific innervated regions in both the CNS and the periphery. Use of fluorescence histochemistry with immunocytochemistry can elucidate catecholamine-peptide relationships. Gelatin-ink perfusion used with fluorescence histochemistry permits the investigation of neuro-vascular relationships and documentation of vascular and parenchymal compartmentation of innervation. Combined use of fluorescence histochemistry and retrograde tracing methods demonstrates the specific cellular sources of innervation of target regions. Micropunch neurochemical analysis provides quantitative data for correlation with fluorescence histochemistry within a target region of innervation, and microspectrofluorometric analysis provides a semi-quantitative evaluation of the amount of fluorophore within a target region or within specific subcellular compartments such as the cell body or terminals.

Microspectrofluorometric characterization of amine accumulation proximal to lateral hypothalamic lesions

Microspectrofluorometry was employed to identify the spectral characteristics of the formaldehyde-induced fluorophore derived from amine accumulation proximal to the site of 6-hydroxydopamine injection or radiofrequency lesions in the lateral hypothalamus of Sprague-Dawley rats. The excitation and emission spectra of the accumulation were consistent with that of catecholamines in models subjected to similar formaldehyde treatment. These results indicate that while biochemical assay technique may not permit the quantification of amine accumulations, these areas do in fact represent degeneration associated increases in catecholamines which may be of functional significance.